tails

American

[teylz] / teɪlz /

adjective

(of a coin) with the reverse facing up.

On the next toss, the coin came up tails.

noun

tailcoat.

tails British

/ teɪlz /

plural noun

an informal name for tail coat

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

interjection

with the reverse side of a coin uppermost: used as a call before tossing a coin Compare heads

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of tails

First recorded in 1675–85; tail ¹ + -s ¹

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

He wanted to take a crack at writing like artists like Billie Eilish, but he couldn’t make heads or tails of it.

From Salon • Mar. 29, 2026

At the end of long straights, the energy tails off and the speed drops, long before the driver brakes for the corner.

From BBC • Mar. 8, 2026

Suddenly, the Irish tails were up and replacement prop Michael Milne burrowed over.

From Barron's • Feb. 5, 2026

Unlike cockroaches and most animals, termite sperm lack tails and are unable to swim.

From Science Daily • Jan. 31, 2026

Weismann had surgically excised the tails of five generations of mice, then bred the mice to determine if the offspring would be born tailless.

From "The Gene" by Siddhartha Mukherjee

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023